How does scultping fit into the workflow?
Generally speaking, sculpting is used either to add details to a model, or the replicate organic organisms. In the former, it is used as a final stage to create a normal map, and does not significantly alter the shape of the model. In the latter, all but the most basic blocking out is done using sculpting, and the topology is created after the fact, using retopology. 

Adding Details

When you use sculpting to add details, those details are generally baked into a normal map. Create a model that fully defines the overall shape of your mesh, and then sculpt fine details on it. Just keep a pre-sculpt copy of the mesh, and then use blender built-in baking features to turn those details into a normal map.

Organic Organisms

While some people do use sculpting to create hard surface objects, this is the exception and a fairly advanced use of sculpting. CG Cookie once made a tutorial on this (requires a subscription) if you are interested.

The majority of users use sculpting to create creatures and characters. Often they model a basic mesh that defines the shape, and then sculpt from there. They will then retopologize the mesh and possibly bake any lost details into a normal map. The retopology makes the mesh animation ready, and brings down the insanely high polygon count.